Device, system and method for low-voltage relay applications

Abstract

The invention relates to a device (10), to a relay unit (250) and to a method (500) for network applications for actuating a relay (100), said device comprising a transformer (20) for converting an input voltage (UE) of the device (10) into an operating voltage (UB), the operating voltage (UB) being configured as a control voltage for a relay coil of the connectable relay (100). Said device also comprises a semiconductor switch (30) for regularly interrupting a current on a primary side of the transformer (20) as well as a controller (40) for actuating the semiconductor switch (30) and a voltage regulator (50) for supplying the controller (40). Furthermore, a current-limiting resistor (60) is provided, which is arranged between an entry contact (C11) of the input voltage (UE) and the primary side of the transformer (20).

Description

[0001] Device, system and method for the application of low-voltage relays

[0002] The present invention relates generally to the field of interface technology with electronic components suitable for measurement, control and regulation tasks, in particular for relays, in the low voltage range.

[0003] The present invention relates to a device that enables the use of relays designed for extra-low voltages (up to approximately 50 V) in the low-voltage range (up to approximately 1 kV). Extra-low voltage relays may be designed and manufactured for the automotive sector. They are generally characterized by good reliability and durability at low cost and with a compact design. However, these extra-low voltage relays are not suitable for use in the low-voltage range. In particular, different safety regulations apply at low voltage, requiring significantly higher voltage withstand ratings during operation and in the event of a fault, such as an overvoltage.

[0004] Low-voltage relays are commercially available and generally comply with the required low-voltage regulations, for example, the insulation requirements of the IEC 60947-1 standard. However, compared to extra-low voltage relays, they have a less compact design and are significantly more expensive.

[0005] Therefore, there is a need to unlock the advantages of relays for extra-low voltages in the low-voltage range as well.

[0006] This problem is solved according to the invention by the features of the independent claims. Further embodiments are described in the dependent claims.

[0007] A first aspect of the invention relates to a device, for example for mains applications, for controlling a relay. The device comprises a transformer for converting an input voltage of the device into an operating voltage, wherein the operating voltage is configured as a control voltage for a relay coil of a connectable relay. The device further comprises a semiconductor switch for periodically interrupting a current on a primary side of the transformer. This periodic interruption can include constant or irregular frequencies. Additionally, the device includes a controller for controlling the semiconductor switch and a voltage regulator for supplying power to the controller.

[0008] Relays are generally known. Therefore, it is only stated here in general terms that a relay is a remotely operated switch, typically with two switching positions, powered by electrical current. The relay is activated via a control circuit and can switch other circuits.

[0009] Transformers, also known as electrical transformers, are used for the galvanic isolation of electrical circuits according to various standards. They can transmit energy, signals, and, additionally or alternatively, data. Planar transformers are also available, in which the individual windings are arranged essentially side-by-side in a single plane. This allows for a flat design, enabling the transformer to be integrated into devices with a low profile.

[0010] Energy transmission or signal transmission can be based on alternating current or can be designed as pulsating direct current.

[0011] An input voltage is applied between the input contacts of the device. In the low-voltage range, this can typically be 230V or 400V AC, with the 400V AC voltage being used in connection with three-phase alternating current, also known as three-phase power or three-phase AC, which constitutes a system for distributing electrical energy. An operating voltage is applied between the operating contacts of the device. It can be, for example, between 2V and 60V, preferably 12V. With a relay coil connected, an operating current generated by the operating voltage flows, which depends on the resistance of the relay coil, in particular its ohmic resistance and its inductance. The inductance changes when the relay closes or opens.

[0012] Applying the control voltage switches the relay into its operating state. Switching off the control voltage returns the relay to its resting state.

[0013] The semiconductor switch interrupts the primary circuit of the transformer. It can be a transistor, for example a field-effect transistor (FET) or a bipolar transistor. It operates as a switch to open or close the primary circuit of the transformer. The regular interruption can cover frequencies between 10 kHz and 10 MHz, typically 100 kHz.

[0014] The voltage regulator can be configured as a voltage regulator for a point-in-place (pP) device or as a voltage divider without regulation for a clock IC. In its pP configuration, the voltage regulator can include both powering the controller and regulating the input voltage. For this purpose, it is connected to the device's input contacts. The controller's power supply can be smoothed by a smoothing element, for example, a capacitor connected to ground.

[0015] Advantageously, such a device can be provided that enables the operation of a low-voltage relay in a low-voltage environment.

[0016] In exemplary embodiments, a separation voltage of between 2 kV and 8 kV, preferably 5 kV, can be implemented between the input voltage that can be applied to the input contacts and the operating voltage that can be applied to the operating contacts of the device. The separation voltage defines the insulation resistance of the device between its input and its output. It is several times higher than the operating voltage and is intended to prevent damage to the device and its downstream components, especially in the event of overvoltage faults. The separation voltages for operation in the low-voltage range are specified by relevant standards, see below.

[0017] This makes it advantageous to meet safety requirements for the low-voltage range even when using low-voltage relays.

[0018] In further embodiments, the control unit can be a processor, microcontroller (pC), or clock generator, for example in the form of a timer IC555 or IC4047. Alternatively or additionally, the device can include a current-limiting resistor arranged between an input contact of the input voltage and the primary side of the transformer. If the primary side of the transformer has a sufficiently high impedance, the resistor can be omitted.

[0019] The control unit is connected to the semiconductor switch and controls the semiconductor switch with a signal designed as a constant switching function.

[0020] The current limiting resistor is located between the live input contact and the primary side of the transformer. As its name suggests, it serves to limit the current, thus preventing unnecessarily high currents on the primary side of the transformer.

[0021] Advantageously, a simple and therefore cost-effective component can be used to control the semiconductor switch. When using a pP (phase-dependent controller), the controller can also perform other tasks, such as voltage measurement, which will be explained in more detail below.

[0022] In other embodiments, the transformer can be planar and, alternatively or additionally, constructed with coils wound on a core. Alternatively or additionally, the transformer can have a disconnect voltage between 0.5 kV and 8 kV, preferably 5 kV. Optionally, the transformer can comply with a basic standard for insulation requirements, in particular DIN EN IEC 60947-1 (VDE 0660-100) for insulation coordinates encompassing overvoltage categories in levels I to IV, IEC 60099-1, and additionally or alternatively, the product standard IEC 60947-5-1.

[0023] Optionally, the transformer can be designed as an intrinsically safe transformer or transformer for isolation amplifiers. Intrinsic safety is generally a technical property of a device or system that, due to specific design principles, ensures that no unsafe condition occurs even in the event of a fault. In this case, intrinsic safety is achieved by the transformer(s) for the galvanic isolation of circuits according to various standards, whereby both energy and signals and / or data can be transmitted via the transformer(s). Advantageously, for example, a required isolation voltage can be achieved simply by using an intrinsically safe transformer. Planar transformers are preferred embodiments for this purpose.

[0024] In exemplary embodiments, the transformer can comprise a layered structure of multiple circuits. This can be particularly applicable to planar transformers. Alternatively or additionally, a first circuit, configured as a primary coil, and a second circuit, configured as a secondary coil, of the transformer can have a minimum insulation thickness between the first and second circuits, for example, 1 mm.

[0025] In this layered structure, only one circuit can be arranged per layer. Alternatively, multiple circuits can be arranged per layer, where the first and second circuits are galvanically isolated from each other and positioned so that they do not come into electrical contact.

[0026] Advantageously, the required separation voltage can be achieved without significantly increasing the volume of the device.

[0027] In further embodiments, the minimum insulation thickness can correspond to the required protection level of the intrinsically safe transformer. Alternatively or additionally, the first circuit and, alternatively or additionally, the second circuit can consist of a plurality of galvanically interconnected sub-circuits. The galvanically interconnected sub-circuits of the first circuit and, alternatively or additionally, the galvanically interconnected sub-circuits of the second circuit can each be arranged vertically one above the other in different layers of the structure.

[0028] The level of protection depends on the voltage used, which in this case can be 230V or 400V. At 400V, also known as the 375V class, the minimum separation distance with solid insulation is, for example, 1 mm, the creepage distance in air is 10 mm, and the creepage distance under a protective layer is approximately 3.3 mm.

[0029] Galvanically interconnected sub-circuits of the first circuit and, alternatively or additionally, of the second circuit can increase the flexibility of the transformer. Furthermore, it can be provided that the sub-circuits of the first circuit are arranged on a first leg of the transformer, while the sub-circuits of the second circuit are arranged on a second leg of the transformer.

[0030] Advantageously, a transformer can be adapted to different requirements by connecting galvanically interconnected sub-circuits for the primary and secondary sides, respectively. This reduces the number of different transformer types, which can result in cost savings. In other embodiments, the processor can tap a measuring voltage across a measuring resistor connected to the primary side of the transformer. The measuring voltage corresponds to (is approximately proportional to) an operating current originating from a secondary side of the transformer. Optionally, a smoothing capacitor can be arranged on the secondary side of the transformer to smooth the coil current on the secondary side. The smoothed coil current no longer exactly corresponds to the coil current. Optionally, the waveform of the operating current can also reflect changes in the inductance of the connectable relay.

[0031] The measuring voltage can be tapped at the measuring resistor on the side of the transformer facing the primary side, following the semiconductor switch. When the measuring voltage is tapped, the control is configured as a pP (positive point contact). The operating current flows between the operating contacts, which are connected to the secondary side of the transformer, when the relay coil of the connectable relay is connected. The measuring voltage can represent a change in the inductance of the connectable relay. The operating current can be a pulsating direct current. A measuring resistor is an ohmic resistor that must meet specific requirements for measurement applications, particularly its precise resistance under various measurement conditions.

[0032] Advantageously, when a relay is activated, the change in inductance measured during the process allows conclusions to be drawn about the condition of the relay, for example, whether it is still functioning properly.

[0033] In exemplary embodiments, the device can include interference suppression circuitry. This interference suppression circuitry can be designed as a capacitor at the operating contacts to smooth the operating current. Furthermore, elements for compensating for electromagnetic interference and, additionally or alternatively, for ensuring electromagnetic compatibility of the device can also be used.

[0034] This also advantageously allows for the reliable function of adjacent components of the device as well as of sensitive connectable relays.

[0035] Another aspect of the invention relates to a relay unit for extending the application of a relay with a current-carrying armature. The relay unit comprises a device according to the first aspect or embodiments thereof. The device can be electrically connected to an input voltage. Furthermore, the device can provide an operating current for a relay coil via operating contacts. The relay has a current-carrying armature with at least one electrical contact. This contact can be provided with contact pins. The contact can be configured as a normally open contact. The relay further comprises a plurality of switching points that are actuated during a switching operation.

[0036] The relay comprises at least the following operating states: relay completely in the rest position, relay in a movement phase which may comprise two sections, and relay in the working position. The current-carrying armature is used as a current conductor to carry the current to the contacts without requiring a separate conductor. The current-carrying armature is equipped with an element of the relay's magnetic system that, in the rest state, is spaced apart from the rest of the relay's magnetic system and, in the working state, establishes electrical contacts by contacting the rest of the magnetic system. The contact points of the magnetic system form electrically closed points through which currents also flow in the working state and in a movement state of the relay.

[0037] Advantageously, a compact design of the relay unit can be achieved through the compact relay, in which, additionally, in the movement state or the operating position of the relay, its inductance is measurably increased by the device through the closing of the current closing points.

[0038] In exemplary embodiments, the plurality of electrical locking points can comprise a first electrical locking point and a second electrical locking point between a pivotable part of the magnetic system (armature) of the relay and a fixed part of the magnetic system (yoke).

[0039] The electrical contacts affect the inductance of the relay coil equipped with the magnetic system. Each closing electrical contact increases the inductance. The inductance increases further with each additional closing electrical contact. Additionally, a portion of the armature current can flow through the closed electrical contacts, as a pivoting part of the magnetic system is attached to the armature.

[0040] Advantageously, the relay's inductance can be varied depending on its state. Furthermore, the proper functioning of the relay can be determined by measuring the change in inductance. This can include both the characteristics of the voltage and current waveforms, as well as the time response of changes in these waveforms.

[0041] In further embodiments, the magnetic system can be designed to be completely closed in one of the relay's operating positions. This includes at least two closed electrical contacts. One contact surface of the first electrical contact is arranged parallel to the relay coil. One contact surface of the second electrical contact is arranged in line with the relay coil.

[0042] The magnetic system can be designed as a rectangle, one leg of which is rotatably mounted. A fixed leg extends through the relay coil. In the relay's resting state, the rotatably mounted leg is folded away by a spring force, thus separating it from the rest of the magnetic system. Its influence on the magnetic system is minimal. In the relay's operating position, the rotatably mounted leg forms a more effective part of the active magnetic system, thereby increasing the inductance of the relay coil. Both current-closing points can be arranged with their contact surfaces at the same height and parallel to each other.

[0043] More precisely, the magnetic system changes continuously even during the movement of the rotatable arm. This change is primarily due to the distances (the air gaps) between the stationary arm and the rotatable arm. The closing of the electrical contacts represents the extreme (particularly large) change in the magnetic system. The inductance increases as the rotatable arm moves towards the stationary arm.

[0044] This makes it advantageous to achieve a structurally simple design, at least for the rotatably mounted leg.

[0045] In other embodiments, when the armature is actuated, the contact and the electrical closing points can close in the sequence contact, first electrical closing point and second electrical closing point, and open in the opposite sequence when the armature returns to its resting position.

[0046] For this purpose, the contact is placed at the free end of the armature. The first electrical contact point is located on the rotating leg near the pivot point, and the second electrical contact point is located on the rotating leg further away from the pivot point. When the armature closes, the contact is closed first, then the first electrical contact point, and finally the second electrical contact point, as described above. Each closing of an electrical contact point measurably increases the inductance, as the pulsating supply current of the relay coil decreases in response to the increased inductance.

[0047] Advantageously, the inductance of the relay can be changed depending on its state. Furthermore, the proper functioning of the relay can be determined by measuring the change in inductance.

[0048] In exemplary embodiments, the contact can be electrically conductive and arranged in series with the first and second electrically conductive switching points connected in parallel.

[0049] The currents flowing through the closed electrical contacts add up due to the parallel circuit. Furthermore, the current flowing through the armature spring adds to the sum of the currents from the electrical contacts, so that the sum of all currents flows through the closed contact and the closed electrical contacts as a total current.

[0050] Advantageously, the ohmic resistance of the armature can be higher without limiting the total current, which allows for the selection of additional materials in the armature's design.

[0051] In further embodiments, the relay unit can be designed for mounting on a DIN rail and with a pluggable receptacle for the relay. DIN rails are known from control cabinet construction and other applications. They are intended for mounting, usually, electrical or electronic components and can be designed as top-hat rails or similar. Components designed for mounting on a DIN rail, for example, the device described, generally have parallel outer walls to allow for space-saving mounting on the DIN rail. They also have fastening means with which the components (devices) can be attached to the DIN rail. The pluggable receptacle for the relay in the relay unit can allow for tool-free relay replacement. Furthermore, the relay unit can be designed to allow the relay to be replaced without opening the unit.The relay's at least one actuated contact can also be routed via the pluggable socket. The relay unit includes terminal blocks for securing electrical conductors.

[0052] This allows for a simple and efficient replacement due to the limited lifespan of the relays.

[0053] A third aspect of the invention proposes a method for extending the application of a relay with a current-carrying armature. This method comprises providing a device according to the first aspect or the associated embodiments. The device is electrically connected to an input voltage via input contacts.

[0054] On the other hand, the device is electrically connected to a relay coil via an operating voltage. The method further comprises providing a relay, wherein the current-carrying armature of the relay has a plurality of current-closing points that are actuated during a switching operation of the relay.

[0055] Advantageously, such a method can be provided that enables the operation of a low-voltage relay in a low-voltage environment.

[0056] Some embodiments of the invention are shown schematically in the drawings and are described in more detail below. They show:

[0057] Fig. 1 shows a schematic representation of a circuit diagram of the device,

[0058] Fig. 2 is a schematic representation of a planar structure of the transformer, Fig. 3 is a diagram of states of selected aspects of the device, Fig. 4 is a schematic representation of a circuit diagram of the relay unit,

[0059] Fig. 5 shows a schematic representation of the relay,

[0060] Fig. 6 shows an electrical equivalent circuit diagram of the relay,

[0061] Fig. 7 shows a constructive embodiment of the relay unit,

[0062] Fig. 8 shows a flowchart of the process for extending the relay application.

[0063] Fig. 1 shows a schematic diagram of the circuit of the device 10. The device 10 is designed for low-voltage network applications to control a low-voltage relay 100 (not shown). The device 10 includes a transformer 20 for converting an input voltage UE of the device 10 into an operating voltage ÜB, the operating voltage ÜB being the control voltage for the relay coil 110 of the connectable relay 100. The device 10 further includes a semiconductor switch 30 for periodically interrupting a current on a primary side of the transformer 20, which is controlled by a signal waveform for the semiconductor switch X2.The device 10 further comprises a control unit 40 for controlling the semiconductor switch 30, a voltage regulator 50 for supplying the control unit 40 and a current limiting resistor 60, which is arranged between the inlet contact C11 of the input voltage UE and the primary side of the transformer 20.

[0064] To operate the device 10 with an alternating voltage UE, an input rectifier 32 and, optionally, a smoothing capacitor 34 are required. The voltage UB must be a direct voltage to drive a relay coil. However, the transformer 20 can only transmit alternating voltages. Therefore, an output rectifier 35 is required on the secondary side of the transformer 20. Furthermore, a freewheeling diode 36 can be provided to limit the back EMF when the relay coil is switched off. Thus, the device can have an input rectifier 32, a freewheeling diode 33, and a smoothing capacitor 34, which, if the input voltage is an alternating voltage, rectifies it into a direct voltage.

[0065] Furthermore, the device 10 can have an output rectifier 35 that rectifies the output voltage of the transformer 20 into a DC voltage UB. In addition, it is advantageous to place a freewheeling diode 36 between terminals C21 and C22, which limits the negative voltage spike (back EMF) that occurs when the coil current is switched off, thus protecting the rest of the circuit from damage or destruction.

[0066] Furthermore, the device 10 has a disconnect voltage (also called rated impulse voltage) between 2 kV and 8 kV, preferably 5 kV, between the input contacts C11 / C12 of the input voltage UE and the operating contacts C21 / C22 of the operating voltage UB, which are designed as a control voltage for a relay coil 110 of the connectable relay 100 (not shown).

[0067] The control unit 40 is designed as a pP 70 or as a clock generator.

[0068] Optionally, the controller 70 can tap a measuring voltage U5 at a measuring resistor 80 connected to the primary side of the transformer 20. A signal from the voltage indicator X3 is then fed to the processor 70.

[0069] The measuring voltage U5 corresponds approximately to an operating current IB originating from a secondary side of the transformer (20) when the relay coil 110 of relay 100 is connected to the operating contacts C21 / C22. The waveform of the operating current IB then reflects the change in inductance of the connectable relay 100 depending on its operating state.

[0070] Fig. 2 shows a schematic representation of a planar structure of the transformer 20. The transformer 20 is designed as an intrinsically safe transformer or as a transformer for isolation amplifiers. The transformer 20 has a planar structure. The transformer 20 has an isolation voltage between 0.5 kV and 8 kV, preferably 5 kV. Optionally, the transformer 20 can comply with a basic standard for insulation requirements, in particular IEC 60947-1.

[0071] The transformer 20 comprises a layered structure of multiple circuits 22 / 26. Additionally or alternatively, the first circuit 22 and the second circuit 26 of the transformer 20 have a horizontally arranged minimum insulation thickness T between the first circuit 22 and the second circuit 26. The minimum insulation thickness can be at least 1 mm.

[0072] The minimum insulation thickness corresponds to the required protection level of the intrinsically safe transformer. Additionally or alternatively, the first circuit 22 and, additionally or alternatively, the second circuit 26 consist of a plurality of galvanically interconnected sub-circuits. The galvanically interconnected sub-circuits of the first circuit 22 and the galvanically interconnected sub-circuits of the second circuit 26 can each be arranged vertically one above the other in different layers (not shown).

[0073] The transformer 20 has a primary coil 22 and a secondary coil 26. The primary coil 22 and the secondary coil 26 each have a contact 24 between parts of the primary coil 22 and the secondary coil 26, respectively. The transformer 20 also has a printed circuit board 28.

[0074] Fig. 3 shows a diagram of the time-dependent states of selected aspects of the relay unit 250. A switch-on pulse is shown at the operating contact C11. After a delay t0-ta, represented by dashed lines, a signal waveform X2 is output to the semiconductor switch 30. The voltage U5, which approximately corresponds to the current I5, develops across the measuring resistor 80 of the relay coil 110 connected to the operating contacts C21 / C22. During this phase, the relay 100 is energized, and its pivoting armature 262 is pulled in. This tensions the armature spring 260. When the contact K1, equipped with the contact pins K29, closes at time tb, the current waveform I5 changes, in particular its slope, by changing more slowly than before. This is because, in addition to the spring force of the armature spring, the spring force of the contact spring must now also be overcome.As the armature spring 260 is further tightened, the first electrical contact K2 closes at time tc. The slope of the current I5 then changes again, increasing once more. When the second electrical contact K3 closes at time td, the slope of the current I5 changes again. Time td is also called the armature strike. Here, the current rises again, in contrast to when contact K1 and the first electrical contact K2 close. This is because the mechanical movement ends after time td, and the current curve corresponds to that of a coil with constant inductance. This relationship can be seen from the dashed lines in the middle of the figure.

[0075] Thus, the operating state of relay 100 can be represented by the current waveform I5, in particular by the corresponding measuring voltage U5.

[0076] Accordingly, it is possible to evaluate the relay state over time. Furthermore, a diagnosis of the relay 100's condition can be made based on these current changes, and deviations from the target sequence before the relay 100 failed can be identified. This also includes temporary deviations from predefined target values.

[0077] Furthermore, the device 10 can include an input and interference suppression circuit (not shown). Fig. 4 shows a schematic representation of a circuit diagram of the relay unit 250. The relay unit 250 serves to extend the application of the relay 100 with a current-carrying armature spring 260. The relay 100 is shown in the switched-on state, with contact K1 closed. In particular, the relay 100 is a low-voltage relay designed for automotive applications, rated for voltages between 10 V and 60 V, typically 12 V, 24 V, and 48 V. The relay unit 250 comprises a device 10 according to the first aspect of the invention or one of its embodiments. The reference numerals from Fig. 1 are adopted where present. The device 10 provides an operating voltage UB via operating contacts C21 / C22, which causes an operating current IB for a relay coil 110 of the relay 100.The remaining reference numerals of the device 10 correspond to the associated reference numerals in Fig. 1.

[0078] Fig. 5 shows a schematic representation of the relay 100. A lockable magnetic system 120 is shown, the pivotable part of which (folding armature) is attached to the armature spring 260. The fixed part of the magnetic system 120 (yoke) is partially enclosed by the relay coil 110.

[0079] The current-carrying armature spring 260 of relay 100 has, in addition to at least one electrical contact K1 with contact pins K29 of a working contact, a plurality of current-closing points K2 / K3, which are actuated during a switching operation of relay 100. The armature current IA flows to contact K1.

[0080] The majority of electrical locking points K2 / K3 comprise a first electrical locking point K2 and a second electrical locking point K3 between a pivotable part of the magnetic system 120 of the relay 100 and a fixed part of the magnetic system 120. The magnetic system 120 is fully closed in the operating position of the relay 100 (armature spring 260 engaged). A contact surface of the first electrical locking point K2 is geometrically parallel to the relay coil 110, and a contact surface of the second electrical locking point K3 is aligned with the relay coil 110.

[0081] When the armature spring 260 is actuated, contact K1 and the electrical locking points K2 / K3 are closed in the following sequence: 1. contact K1, 2. first electrical locking point K2, and 3. second electrical locking point K3. When the armature spring 260 returns to its resting position, contact K1 and electrical locking points K2 / K3 are opened in the reverse order.

[0082] The contact K1 is electrically conductive and arranged in series with the parallel connected first electrical locking point K2 and second electrical locking point K3.

[0083] Fig. 6 shows an equivalent circuit diagram of the relay. The explanation refers to Fig. 5, which uses some of the same reference symbols. Relay 100 is shown in detail as a circuit diagram in Fig. 6.

[0084] The ohmic resistance of the armature spring 260 is represented as the third resistor R3. The ohmic resistance of the armature pivot shaft 265 (see Fig. 5) is represented as the first resistor R1. The first current-closing point K2 (see Fig. 5) is shown by K2 and a second resistor R2. The second current-closing point K3 (see Fig. 5) is shown by K3 and a fourth resistor R4 of the magnet system 120. The first contact K1 represents contact K1 from Fig. 5. A corresponding current 11-14 (not shown) flows through each of the resistors R1-R4 when the circuits are closed.

[0085] Contact K1 and electrical locking points K2 and K3 are actuated by a closing movement of the armature spring 260. The first electrical locking point K2 is delayed by a first switching time T1 relative to the actuation of contact K1. The second electrical locking point K3 is delayed by a second switching time T2 relative to the closing of the first electrical locking point K2. The switching-off sequence is reversed.

[0086] Fig. 7 shows a structural embodiment of the relay unit 250. The relay unit 250 is designed for mounting on a mounting rail (not shown) with a mounting rail adapter 280 and with a pluggable receptacle 270 for the relay 100. The mounting rail is designed as a DIN rail. Furthermore, the relay unit 250 comprises a plurality of spatially separated contact elements for electrical contacting and securing wires. The relay unit is essentially disc-shaped. The width and depth of the relay unit 250 have a ratio of up to 1:15, and at least 1:10. Fig. 8 shows a flowchart of the method 500. The method 500 serves to extend the application of a low-voltage relay 100 with a current-carrying armature spring 260 for use in the low-voltage range.

[0087] It comprises providing a device 10 according to the first aspect of the invention or the associated embodiments. The device 10 is electrically connected to an input voltage UE via input contacts C11 / C12. The device is also electrically connected to a relay coil 110 of the relay 100 via the operating voltage UB. Additionally, at least the contact K1 of the armature spring 260 is connected to the device 10. Contact K1 is mentioned here by way of example and represents all possible contact configurations of relays, including multiple contacts, changeover contacts, and the like.

[0088] Furthermore, the procedure 500 includes the provision 350 of a relay 100. The current-carrying armature spring 260 of the relay 100 has a plurality of current-closing points K2 / K3, which are actuated during a switching operation of the relay 100.

[0089] In other words, the invention can be described as follows: the invention serves to improve galvanic isolation and thus the use of a low-voltage automotive relay 100 on the low-voltage network for industrial use.

[0090] The start process for controlling relay 100 is initiated by supplying power at input C11 (see Fig. 1). The supplied voltage is stabilized by a voltage regulator 50 and buffered at the regulator's output with a capacitor to supply a controller (40) or microcontroller (70). The voltage UB at the controller can be 3.3V. A controller 40 controls the transformer 20 via a transistor-based semiconductor switch 30, thereby providing the necessary energy (via a high-frequency signal) for relay 100. After rectification and smoothing, this energy is then made available as voltage UB at the operating contacts C21 / C22.

[0091] Since the current I5 through the measuring resistor R5 is proportional to the voltage U5, this can be made available to the processor 70 for further processing via the voltage indicator X3.

[0092] Because the magnetic system 120, designed as a magnetic circuit, assumes different mechanical positions in the relay 100 during a switching sequence, the position of the armature (folding armature) 262 can be determined by monitoring the voltage indicator X3.

[0093] The following states of relay 100 are distinguished, as illustrated in Fig. 3:

[0094] to > Relay is fully open, in particular the armature spring 260 is in its rest position ta > Relay is energized and is in the movement phase, overcoming the armature spring force

[0095] tb > The relay is in a movement phase overcoming the armature spring force and the contact spring force; contact K1 is already closed.

[0096] tc > The relay is in the movement phase, overcoming the armature spring force and the contact spring force; contact K1 and the first electrical closing point K2 are closed.

[0097] td > Relay in operating state, movement phase is complete, contact K1, the first electrically closed point K2, and the second electrically closed point K3 are closed. The following is a description of the automotive relay 100 with a current-carrying armature 260. The construction differs from conventional relays 100 in the current-carrying armature spring 260. Here, the armature spring 260 is used as a current conductor to supply current to contact K1 without the need for an additional conductor. The armature spring 260 also carries the armature current IA, as shown in Fig. 5.

[0098] More precisely, the current IA flows into terminal C31 at the bottom left, passes through the yoke on the left side, then flows into the armature spring 260, and then out via contact K1 to the right terminal C32. When the relay is in its operating position (not shown), an additional (almost negligible) portion of the current IA flows electrically parallel to the armature spring 260 through the movable armature (flap armature) 262 via the current-shooting points K2 and K3.

[0099] The first electrical locking point K2 and the second electrical locking point K3 always close and open in a mechanically predetermined sequence.

[0100] In the switching-on sequence, contact K1 closes first, then a contact spring is tensioned in an overtravel area so that the first electrical closing point K2 can also close.

[0101] As a final phase, the armature spring tightens again, so that the armature 260 now lies flat against the coil core of the magnet system 120, thereby also closing the second current-closing point K3.

[0102] The armature spring carries the armature current IA and is connected to the magnetic system 120 by spot welds (not shown). For better understanding, the electrical structure of the relay 100 is detailed as a circuit diagram in Fig. 6, where the electrical connection of the armature spring of the armature 260 is shown schematically as a line.

[0103] The ohmic resistance of the armature 260 is represented as the third resistor R3. The ohmic resistance of the armature's rotating shaft 265 is represented as the first resistor R1. The first current-closing point K2 (see Fig. 5) is shown by K2 and a second resistor R2. The second current-closing point K3 (see Fig. 5) is shown by K3 and a fourth resistor R4 of the magnet system 120. The first contact K1 represents contact K1 from Fig. 5. A corresponding current 11-14 (not shown) flows through each of the resistors R1-R4 when the circuits are closed.

[0104] Contact K1 and electrical contacts K2 and K3 are actuated by a closing movement of the armature 260. The first electrical contact K2 closes with a delay of one switching time T1 relative to the closing of contact K1. The second electrical contact K3 closes with a delay of one switching time T2 relative to the closing of the first electrical contact K2. The switching-off sequence is inverse. As the first electrical contact K2 and the second electrical contact K3 close, progressively lower resistance values ​​are established in a load current path of the relay 100, resulting in progressively smaller power losses.

[0105] Since the main load current always flows through contact K1, because its design, particularly the contact pins K29, and the switching sequence are specifically tailored for this purpose, any arcing that occurs during switching also takes place here. This means that the first current switching point K2 and the second current switching point K3 only assist in the process, and the load paths experience a reduction in impedance (lower-impedance switching).

[0106] The following phases can be identified for extracting information from the current I5:

[0107] 1. Flight phase of anchor 260 between ta and tb

[0108] 2. Contact moment at contact K1 (K1 is closed from this point on) due to the first magnetic change after the flight phase

[0109] 3. Contact torque at the first electrical closing point K2 due to further magnetic oscillation

[0110] 4. Contact moment at the second electrical locking point K3 upon reaching the final phase (overstroke phase completed)

[0111] It is understood that variants of the above-disclosed features and other characteristics and functions or alternatives thereof can be combined as desired to form many other different systems, applications, or processes. Various currently unforeseen and unexpected alternatives, modifications, variations, and improvements may subsequently be implemented by those skilled in the art, and these are also intended to be encompassed by the following claims. Reference numerals

[0112] 10 Device

[0113] 20 transformers

[0114] 22 Primary coil

[0115] 24 Contact

[0116] 26 Secondary coil

[0117] 28 circuit boards

[0118] 30 semiconductor switches

[0119] 32 input rectifiers

[0120] 33 Freewheeling diode

[0121] 34 Smoothing capacitor

[0122] 35 Output rectifiers

[0123] 36 Freewheeling diode

[0124] T1 Minimum insulation thickness

[0125] X2 Signal waveform for semiconductor switch X3 Voltage indicator

[0126] 40 Control

[0127] 50 voltage regulators

[0128] 60 Current limiting resistor

[0129] 70 processor, pP

[0130] 80 measuring resistor

[0131] I5 Measuring current

[0132] 100 relays

[0133] 110 Relay coil

[0134] 120 magnetic system

[0135] UE input voltage

[0136] UB operating voltage

[0137] C11, C12 input contacts

[0138] 021, 022 Operating contacts C31, C32 Output contacts

[0139] U5 Measuring voltage

[0140] IB operating current

[0141] 250 relay unit

[0142] 260 (current-carrying) armature spring

[0143] 262 (pivoting) anchor (hinged anchor) 265 anchor rotation axis

[0144] 267 coil core

[0145] IA Armature current

[0146] K1 Contact

[0147] K2 first electrical locking point

[0148] K3 second electrical locking point

[0149] R1 first resistor

[0150] R2 second resistor

[0151] R3 third resistor

[0152] R4 fourth resistor

[0153] K29 contact pills

[0154] T1 first switching point

[0155] T2 second switching point

[0156] 270 pluggable slots

[0157] 280 mounting rail adapters

[0158] 300 Providing a device 350 Providing a relay

[0159] 500 procedures

Claims

Claims 1. Device (10) for controlling a relay (100), comprising a transformer (20) for converting an input voltage (UE) of the device (10) into an operating voltage (UB), wherein the operating voltage (UB) is configured as a control voltage for a relay coil of the connectable relay (100), a semiconductor switch (30) for regularly interrupting a current on a primary side of the transformer (20), and a controller (40) for controlling the semiconductor switch (30), a voltage regulator (50) for supplying power to the controller (40).

2. Device (10) according to claim 1, wherein the device (10) has a separation voltage between 2 kV and 8 kV, preferably 5 kV, between the input contacts (C11, C12) of the input voltage (UE) and the operating contacts (C21, C22) of the operating voltage (UB) designed as a control voltage for a relay coil (110) of the connectable relay (100).

3. Device (10) according to one of claims 1-2, wherein the controller (40) is configured as a processor (70) or as a clock generator and / or a current limiting resistor (60) which is arranged between an inlet contact (C11) of the input voltage (UE) and the primary side of the transformer (20).

4. Device (10) according to one of claims 1-3, wherein the transformer (20) is planar and / or constructed with coils wound on a core and / or wherein the transformer (20) has a separation voltage between 0.5kV and 8kV, preferably 5kV, optionally wherein the transformer (20) complies with a basic standard for insulation requirements, in particular IEC 60947-1.

5. Device (10) according to any one of claims 1-4, wherein the transformer (20) comprises a layered structure of a plurality of circuits and / or wherein a first circuit (22) designed as a primary coil (22) and a second circuit (26) designed as a secondary coil (26) of the transformer (20) has a minimum insulation thickness of an insulation between the first circuit (22) and the second circuit (26).

6. Device (10) according to claim 5, wherein the minimum insulation thickness corresponds to the required protection level of the intrinsically safe transformer and / or wherein at least the first circuit (22) and / or the second circuit (26) consists of a plurality of galvanically interconnected sub-circuits, wherein the galvanically interconnected sub-circuits of the first circuit (22) and / or the galvanically interconnected sub-circuits of the second circuit (26) are each arranged vertically one above the other in different positions of the layer structure.

7. Device (10) according to one of claims 3-6, wherein the processor (70) taps a measuring voltage (U5) at a measuring resistor (80) connected to the primary side of the transformer (20), wherein the measuring voltage (U5) corresponds to an operating current (IB) emanating from a secondary side of the transformer (20) when the relay coil (110) of the relay (100) is connected; optionally wherein the waveform of the operating current (IB) represents the inductance change of the connectable relay (100).

8. Device (10) according to one of claims 1-7, wherein the device (10) comprises an input and interference suppression circuit.

9. Relay unit (250) for extending the application of a relay (100) with a current-carrying armature (260), comprising a device (10) according to one of the preceding claims, wherein the device (10) provides an operating current (IB) for a relay coil of the relay (100) via output contacts (C31, C32), and the relay (100), wherein the current-carrying armature (260) of the relay (100) has, in addition to the at least one electrical contact (K1) with contact pills (K29) listed as a working contact, a plurality of current-closing points (K2, K3) which are actuated during a switching operation of the relay (100).

10. Relay unit (250) according to claim 9, wherein the majority of electrical locking points (K2, K3) comprise a first electrical locking point (K2) and a second electrical locking point (K3) between a pivotable part of the magnetic system (120) of the relay (100) and a fixed part of the magnetic system (120).

11. Relay unit (250) according to claim 9 or 10, wherein the magnetic system (120) is designed to be completely closed in an operating position of the relay (100), and wherein a contact surface of the first electrical switching point (K2) is arranged parallel to the relay coil (110) and a contact surface of the second electrical switching point (K3) is arranged in extension to the relay coil (110).

12. Relay unit (250) according to one of claims 9-11 , wherein when the armature (260) is actuated the contact (K1 ) and the electrical closing points (K2, K3) close in the sequence contact (K1), first electrical closing point (K2) and second electrical closing point (K3), and when the armature (260) returns to its original position they open in the opposite order.

13. Relay unit (250) according to one of claims 9-12, wherein the contact (K1) is electrically conductive in series with the parallel connected first current closing point (K2) and second current closing point (K3).

14. Relay unit (250) according to one of claims 9-13, wherein the relay unit (250) is designed for mounting on a mounting rail and with a pluggable receptacle (270) for the relay (100).

15. Method (500) for extending the application of a relay (100) with a current-carrying armature (260), comprising the following steps: providing (300) a device (10) according to one of claims 1-9, wherein the device (10) is electrically connected on the one hand to an input voltage (UE) via input contacts and on the other hand to a relay coil of the relay (100) via an operating voltage (UB), and providing (350) the relay (100), wherein the current-carrying armature (260) of the relay (100) has a plurality of current-closing points (K2, K3) which are actuated during a switching operation of the relay (100).

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